iOS: Changing min SDK Version of App in Apple's Store

I have released an App in the App Store with target platform 5.1. The app also was developed using SDK 5.1. My customer phoned me and said this is crap because als the jailbroken phones aren't able to download the app yet - because there is currently no jailbroken version for 5.1.

What do I have to do? I'm coming from Android - therefore I want to be really sure what I am doing when applying an App update to ensure that it is also available for 5.0 users.

I also use a Library Project - which also uses SDK 5.1 as shown in the screenshot below.

My App SDK

I would be really glad about some instructions how to reduce the required version for the app and if there are some compatibility troubles/problems occurring to my code when I do this.

Solution

You should change the deployment target, in the summary tab of the target, as shown in the image:

Set deployment target

And call your customer and tell him there is already Jailbreak for 5.1 ;)